Before the doors opened at the Experience Music Project, the Bumbershoot opening act could not be found backstage.

Instead, Great Waves members sat in the corner on the concrete floor near the entrance, using the polished surface as a drum set. Singer Ashley Bullock led the group in a last-minute rehearsal as hip-hop played incongruously in the background

Months after the Sammamish band prevailed in a battle of the bands to earn the opening slot at the largest music fest in the Northwest, members patiently waited through the last moments before a career-defining performance.

“Ready — kind of, sort of,” Bullock said.

Bassist Paul Beeman, in typical fashion, lowered expectations as members headed into the morning sound check.

The band usually plays at night, often in places cursed by bad acoustics — but the Sky Church is blessed. The band praised the professional sound engineers for accommodating some extra musicians, including a couple of spare drummers, a violinist and a trumpeter.

Finally, at about noon, the doors opened for the 12:30 p.m. set. The crowd started to filter inside as the band members finished up the impromptu rehearsal, just feet from the door.